JP2010285581A - Insulating resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive polyphenylene sulfide resin composition having high heat conductivity while maintaining good physical properties such as insulating properties, fluidity, and low linear expansion possessed by the polyphenylene sulfide resin. <P>SOLUTION: The resin composition includes the polyphenylene sulfide resin; talc which is a platy particle having a 50% particle diameter (D<SB>50</SB>) based on the volume distribution of ≥10 μm; and glass fibers so that, based on the sum of volumes of each component, the volume of the talc is 5-45 vol.%; the volume of the glass fibers is 0-30 vol.%; and the sum of the volumes of the talc and glass fibers is 30-55 vol.%. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a polyphenylene sulfide resin composition imparted with high thermal conductivity by blending plate-like talc particles as a filler and a resin molded body formed from the resin composition.

  Since the polymer compound is an insulating material excellent in moldability, it is used for various electronic parts such as a base for an electronic circuit board, a motor insulating material, and an insulating adhesive. In particular, polyphenylene sulfide is a crystalline heat-resistant polymer, has high strength and rigidity, is excellent in flame retardancy, oil resistance, and dimensional stability, and is widely used in electronic parts.

In recent years, with the increase in density and output of electronic components, the amount of heat generated from the electronic components has increased. For this reason, measures for releasing heat of electronic components are strongly demanded.
2. Description of the Related Art Conventionally, resin materials have been developed in which a high heat dissipation filler (filler) is mixed with a high-temperature heat-resistant resin such as polyphenylene sulfide to impart thermal conductivity.

  Carbon fiber, silica, alumina, boron nitride, aluminum nitride, magnesia and the like are known as the high heat dissipation filler. Although the resin material containing such a high heat dissipation filler has high heat dissipation, there are problems such as lack of insulation, expensive material, low heat resistance, and hardness, which easily deteriorates the molding machine. Therefore, the resin material containing the high heat dissipation filler has a limit in the environment and conditions in which the material is used. Patent documents 1 and 2 are mentioned as an example of a resin material which blended a high heat dissipation filler.

  In Patent Document 1, a basic oxide such as magnesium oxide, aluminum oxide, beryllium oxide, or magnetic powder is provided as a filler for the purpose of imparting thermal conductivity to a heat-resistant thermoplastic resin composition. It is described. However, since this heat resistant thermoplastic resin composition has conductivity, it is not suitable for use as an insulating material.

  Patent Document 2 discloses that thermal conductivity is imparted by adding boron nitride as a filler to a polyarylene sulfide resin composition. However, there is a problem that boron nitride is expensive.

  On the other hand, it has been difficult to achieve high thermal conductivity with existing materials blended with inexpensive fillers such as magnesium carbonate. For example, Patent Document 3 discloses a polyphenylene sulfide resin composition in which 50 to 300 parts by weight of magnesium carbonate and 10 to 100 parts by weight of glass fiber are blended with 100 parts by weight of polyphenylene sulfide resin. It is disclosed as a material having both conductivity. However, since magnesium carbonate has low thermal conductivity, the thermal conductivity of the resin composition was not satisfactory.

Japanese Patent Publication No. 4-9185 JP 2008-248048 A JP 2007-246883 A

As described above, no satisfactory high thermal conductivity resin material having physical properties such as insulation, high fluidity, and low linear expansion has been conventionally provided.
Therefore, the present invention should solve the problem of providing an inexpensive polyphenylene sulfide resin composition having high thermal conductivity while maintaining good physical properties such as insulation, fluidity, and low linear expansion of the polyphenylene sulfide resin. Let it be an issue.

Surprisingly, the inventor of the present invention includes a polyphenylene sulfide resin, a talc that is a plate-like particle having a 50% particle size (hereinafter referred to as “D ₅₀ ”) based on volume distribution of 10 μm or more, and glass fiber. The volume of the talc is 5 to 45 vol%, the volume of the glass fiber is 0 to 30 vol% with respect to the sum of the volumes of the polyphenylene sulfide resin, talc and glass fiber, and the talc and the glass fiber It has been found that the resin composition contained so that the sum of the volumes of 30 to 55 vol% has high thermal conductivity, excellent insulation and fluidity, and a low coefficient of linear expansion.
The present invention also relates to a resin molded body obtained by molding the resin composition.

  The resin composition and resin molded body of the present invention have high thermal conductivity, excellent insulation and fluidity, and a low linear expansion coefficient. The resin composition and the resin molded body of the present invention can be manufactured at a lower cost than a conventional heat conductive resin material using a high heat dissipation filler.

FIG. 1 is a graph in which each data shown in Table 2 is plotted with the feeder total filling rate on the horizontal axis and the thermal conductivity on the vertical axis. FIG. 2 is a graph in which the data shown in Table 2 are plotted with the feeder total filling rate on the horizontal axis and the linear expansion rate on the vertical axis. FIG. 3 is a graph in which each data shown in Table 2 is plotted with the feeder total filling rate on the horizontal axis and the 0.3 mm spiral length on the vertical axis.

で表される繰り返し単位を主成分として（例えば７０モル％以上、好ましくは９０モル％以上、より好ましくは９５モル％以上）含有する熱可塑性の耐熱高分子化合物である。ＰＰＳ樹脂の分子量は特に限定されず、種々の分子量のものを使用することができる。また、高分子鎖末端に種々の修飾基が導入されたＰＰＳ樹脂も使用することができる。ＰＰＳ樹脂としては電子部品の用途において一般に使用されているものであれば特に限定なく使用することができる。 1. The material polyphenylene sulfide resin (hereinafter sometimes referred to as “PPS resin”) is

Is a thermoplastic heat-resistant polymer compound containing as a main component (for example, 70 mol% or more, preferably 90 mol% or more, more preferably 95 mol% or more). The molecular weight of the PPS resin is not particularly limited, and various molecular weights can be used. Also, PPS resins having various modifying groups introduced at the ends of the polymer chain can be used. Any PPS resin can be used without particular limitation as long as it is generally used in applications of electronic components.

Talc is a natural mineral having a plate-like particle shape. Platy talc D ₅₀ of the particles increases the thermal conductivity of the formed by molding a resin composition molded resin when it is 10μm or more. Further, D ₅₀ is 10μm or more platy talc particles is less expensive than a particle of a small particle size. The upper limit of D ₅₀ of the plate-like talc particles is not particularly limited, but is typically 30 μm or less. Inside the resin molded body obtained by molding the resin composition of the present invention containing such plate-like talc particles as a filler, the plate-like talc particles are connected to form a heat conduction path to efficiently conduct heat. Is estimated to be possible. In the present invention, D ₅₀ of the plate-like talc particles refers to a 50% particle size based on a volume distribution measured by a laser diffraction / scattering particle size distribution measuring apparatus (for example, Microtrack 9220FRA (Leeds & Northrup)).

  The glass fiber is not particularly limited and can be used as long as it is generally blended with the PPS resin. The glass fiber usually has a cross section with a diameter of 5 to 15 μm and a length of about 0.1 to 30 mm. The shape of the cross section is not particularly limited.

  The resin composition of the present invention may further contain other components. For example, usual additives such as various surface modifiers, coupling agents, plasticizers, mold release agents, and pigments may be blended in the resin composition of the present invention within a range not impairing the effects of the present invention.

2. Composition The resin composition of the present invention comprises the polyphenylene sulfide resin, talc, and glass fiber, wherein the volume of the talc is 5 to 45 vol% with respect to the sum of the volumes of these components, and the glass fiber The volume is 0-30 vol%, and the total volume of the talc and the glass fiber is 30-55 vol%. Hereinafter, the ratio of the volume of talc and / or glass fiber to the sum of the volumes of polyphenylene sulfide resin, talc and glass fiber is referred to as “filling rate”.

  When the filling rate of talc is 5-45 vol% and the filling rate of glass fiber is 0-30 vol%, the high fluidity of the resin composition is maintained. A resin composition containing no glass fiber, that is, a glass fiber filling rate of 0 vol% is also included in the present invention. In this case, the filling rate of talc may be 30 to 45 vol%.

  When the total filling rate of talc and glass fiber is less than 30 vol%, the thermal conductivity of the molded product obtained by molding the resin composition is less than 0.6 W / mK. On the other hand, if the total filling rate of talc and glass fiber exceeds 55 vol%, the fluidity of the resin composition is deteriorated. When the total filling rate of talc and glass fiber is 30 to 55 vol%, the resin composition has high fluidity, and the formed molded article has high thermal conductivity (0.6 W / mK). This is preferable.

  In addition, the thermal conductivity of a normal PPS resin molded body (containing about 30 vol% of glass fibers or about 60 vol% of glass fibers and calcium carbonate in total) is about 0.25 to 0.4 W / mK. .

The value of the filling rate is the weight of each component (polyphenylene sulfide resin, talc, glass fiber) (example of unit: g), and the true density of each component (density as a solid excluding voids) (example of unit: g). / Cm ³ ) to calculate based on the true volume (unit example: cm ³ ) calculated by dividing by.

3. Production Method The resin composition of the present invention can be produced using a kneader such as a single-screw extruder, a twin-screw extruder, a Banbury mixer, or a hot roll. Addition and mixing of each component to the kneader may be performed simultaneously or in divided portions. The kneading treatment is usually performed at a temperature exceeding the melting point of the polyphenylene sulfide resin.
The resin molded body of the present invention can be formed by molding the resin composition by a method such as injection molding, extrusion molding, injection compression molding or the like.

4). Application The resin molded body formed from the resin composition of the present invention can be suitably used as a material for electronic parts and the like that are required to have thermal conductivity.

[Example]
The present inventors filled a thermoplastic polyphenylene sulfide (PPS) resin with four kinds of natural mineral fillers and glass fibers to produce a resin molded body. Samples (Examples 1 to 6 and Comparative Examples 1 to 23) having different types and particle sizes (D ₅₀ ) of natural mineral fillers and filling rates of natural mineral fillers and glass fibers were prepared, and thermal conductivity and linear expansion coefficient were obtained. The fluidity (0.3 mm spiral length) was measured.

1. Materials Details of the materials used in this example are summarized in Table 1.

2. Resin molded body preparation procedure The raw material components in the blending ratio shown in Table 2 were kneaded by a co-rotating twin screw extruder, and the resulting compound was molded to obtain a pellet. A pellet-shaped material was injection-molded to prepare a dumbbell-shaped resin molded body test piece.

The conditions for obtaining pellets are as follows:
Extruder: Co-rotating twin screw extruder Setting speed: 310 ° C
Screw rotation speed: 100rpm
Feed rate: 15kg / h
Pelletizer speed: 26m / min

3. Measuring method
3.1. Measurement of thermal conductivity The thermal conductivity was measured in accordance with JIS R1611. The sample thickness was 1 mm.

3.2. Measurement of linear expansion coefficient The linear expansion coefficient was measured in accordance with ISO 11359-2. The measurement temperature was −40 to 160 ° C.

3.3. Measurement of fluidity (0.3 mm spiral length) Using a spiral mold having a width of 10 mm, a thickness of 0.3 mm, and a length of 600 mm, molding was performed by injection molding, and the length of the obtained molded product was measured. (The longer the material, the longer the length of the molded product.)
The resin temperature during molding was 310 ° C., the mold temperature was 150 ° C., and the injection speed was 200 mm / s.

4). The results are shown in Table 2. When the thermal conductivity was 0.6 W / mK or more, it was evaluated that the thermal conductivity was good. When the spiral length was 30 mm or more, it was evaluated that the fluidity was good. Although no threshold was set for the linear expansion coefficient, it can be said that the smaller the value, the better the material.

FIG. 1 plots the data shown in Table 2 with the feeder total filling factor on the horizontal axis and the thermal conductivity on the vertical axis.
In FIG. 2, each data shown in Table 2 is plotted with the feeder total filling rate on the horizontal axis and the linear expansion rate on the vertical axis.
In FIG. 3, each data shown in Table 2 is plotted with the feeder total filling rate on the horizontal axis and the 0.3 mm spiral length on the vertical axis.

5. Discussion As a natural mineral filler, a resin molded body using mica, kaolin, or calcium carbonate had a thermal conductivity of less than 0.6 W / mK. Moreover, many of the resin moldings using talc having a D ₅₀ of less than 10 μm had a thermal conductivity of less than 0.6 W / mK. On the other hand, in the resin molded body using talc having D ₅₀ of 10 μm or more, the thermal conductivity tends to increase as D ₅₀ increases. _Further, talc is less than _{D 50} of 10μm _is more expensive than _{D 50} of the 10μm or talc. Therefore, in order to realize high thermal conductivity at low cost, it can be said that it is preferable to use plate-like talc having a D ₅₀ of 10 μm or more as the natural mineral filler.

  In Examples 1-6, when the filling rate of talc increases in the range of 20-40 vol%, a tendency to decrease the spiral length (fluidity) is recognized, and in Comparative Example 8 using 50 vol% talc, the spiral length Showed a low value of 23 mm. Therefore, in order to maintain the fluidity | liquidity of a resin composition, it turns out that it is preferable that the filling rate of talc is 5-45 vol%.

  From the comparison of Examples 1, 5, and 6 in which the glass fiber filling rate was 10, 20, and 30 vol%, respectively, the higher the glass fiber filling rate, the lower the spiral length (fluidity). If the rate exceeds 30 vol%, it is suggested that the spiral length (fluidity) is less than 30 mm. Moreover, it is estimated that a favorable thermal conductivity is maintained even if the glass fiber is 0 vol%. Therefore, it is preferable that the filling rate of glass fiber is 0-30 vol%.

  Resin molded bodies (Comparative Examples 1 to 5 and 9) in which the total filling rate of talc and glass fibers (“filler total filling rate” in Table 2) is less than 30 vol% have low thermal conductivity. On the other hand, in the formulations of Examples 1 to 6, it can be seen that the spiral length (fluidity) decreases as the value increases within the range of 30 to 50 vol% of the total filling rate of talc and glass fiber. When the total filling rate of talc and glass fiber was 60 vol% (Comparative Example 8), the spiral length was a very low value of 23 mm. Therefore, from the viewpoint of improving thermal conductivity and maintaining fluidity, the total filling rate of talc and glass fiber is preferably 30 to 55 vol%.

Since as described above, talc and the glass fibers, relative to the total volume of the PPS _{resin, D 50} is more than the plate-like talc particles 10μm 5~45 vol%, 0~30vol% glass fibers, talc And glass fiber in a total content of 30 to 55 vol%, a high thermal conductivity (0.6 W / mK or more), a low linear expansion coefficient, a high fluidity (the length of the spiral method) It can be concluded that an insulating member having a thickness of 30 mm or more can be manufactured at a low cost.

Claims (2)

A polyphenylene sulfide resin, a talc which is a plate-like particle having a 50% particle size (D ₅₀ ) of 10 μm or more based on volume distribution, and a glass fiber are added to the sum of the volumes of the polyphenylene sulfide resin, the talc and the glass fiber. The resin composition is contained so that the volume of the talc is 5 to 45 vol%, the volume of the glass fiber is 0 to 30 vol%, and the sum of the volumes of the talc and the glass fiber is 30 to 55 vol%. object.   A resin molded product obtained by molding the resin composition of claim 1.

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